2. Do I really have to batch process as 16 bit? Don't wanna donate so much money to HD makers... Will 8 bit do it ?

Here's why 16-bit - because it lets you output from SPP with exposure reduced to recover highlights, and then bring exposure back up in whatever program you import to with no banding in the shadows.

Also if you are using a wider color space like ProPhoto or AdobeRGB, it will help preserve subtle differences in color. Since that was one of the things that interested you about the camera, it is a good idea to preserve it!

What I do to mitigate the space issue is I first go through the JPG's and review for content and sharpness, then only batch process in SPP the RAW files I want to do further work with.

3. Now something I've never tried before and need your help: when I open those exported TIFFs in Camera RAW, will they have the same latitude as real RAWs ?....

If you export as 16-bit TIFF files, sort of - but not in terms of highlight recovery, that's something that has to be done in SPP.

I shoot the Merril cameras with a +0.7 exposure bias, with the intent to slightly blow highlights - then in SPP I batch export all images at -1.0 to -2.0 exposure (using a preset), so that SPP recovers the highlights blown - then in Aperture I add the exposure back in in bulk to the original levels. At that point I can use things like the recovery sliders because the highlight data is now preserved... Camera RAW may behave the same way.

Again the 16-bit TIFF file is important to preserve changes in tone and color as it goes from a dark but recovered highlight image back to a normal image where you adjust tones.

Edit: also a good idea to shoot ISO 200 for maximum highlight recovery (does not impact sharpness but slightly increases noise in smooth areas like the sky)

Email me and I'll send you a few images with highlights blown out a bit so you can experiment.